Drying apparatus



F. T. DOW.

DRYING APPARATUS.

APPLICATION FILED APR. 29, 1919.

Patented J nly 20, 1920'.

2 SHEETS-SHEET I.

InvenTor. Fred T. Dow byMSwZZiW/f F; T. 00w.

DRYING APPARATUS.

APPLICATION FILED APR. 29, 1919.

Patented uly 20, 1920 2 SHEETS-SHEET 2.

Fig. 3. I5 '9 a I a u I00 5 I06 lnvmor. Fred -T. Dow w zsmm Anya . UNITED STATES FRED T. DOW, OF BANGOR, MAINE.

Specification of Letters Patent.

DRYING APPARATUS.

Patented July 20, 1920.

Application filed April 29, 1919. Serial 170,293,386.

To all whom it may concern:

Be itknown that I, Fnnn T. Dow, a citizen'of'the United States, residing at Bangor, county'of Penobscot, State of Maine, have invented an Improvement in Drying Apparatus, of which the following description, in connection with the accompanying drawing, is a specification, like characters on the drawing representing like parts.

This invention relates to drying apparatus capable of use for drying peat, coal, lignite, sawdust, fruits, vegetables, and other material either in granular or fragmentary form, and has for its object to provide a novel drying apparatus by which material can be quickly dried in an economical manner.

My improved apparatus comprises a drying chamber, a plurality of reticulated carriers or trays adapted to contain the material to be dried and arranged to pass successively through the drying chamber-from one end to the other thereof, means iorcausing a drying medium to pass through the drying chamber, preferably in a direction opposite to that in which the material to be dried is moving so that said medium passes through the reticulated carriers successively, and means for delivering the material to be dried to the separate carriers at one end or the drying chamber.

here the device is used for drying peat or similar material, I propose 'to use a device in connection with the drying apparatus which will operate to grind the raw material and reduce it to a homogeneous state,

and then to form and compress said material into small pencil-like fragments which are delivered to the carriers and pass through the drying chamber in this form.

I have also illustrated herein a press or similar device forforming the dried material into cakes or briquets. r

In order to give an understanding of my invention, I have illustrated in the drawings 7 some selectedembodiments thereof which will now be described, after which the novel features will be pointed out in the appended claims.

In the drawings, Figure l is a side view ing my invention;

F ig; 2 is an enlarged section through the drying chamber on substantially the line 2-42, Fig. 1;

Fig. 3 is a section on the line 33, Fig. 1;

)artly in section of an apparatus embody- Fig. e is an enlarged view of the grinding apparatus.

In my improved apparatus, the drying is done in a chamber 1 which is herein shown as being an elongated chamber placed in an lnclined position. The material to be dried is carried through the drying chamber by means of suitable carriers 2 which are in the form or". reticulatedplatforms and are arranged to pass longitudinally through the chamber 1. This movement 01" the carriers will preferably be accomplished by connecting them together by some suitable means so thatthey will move as a unit. One convenient way of accomplishing this is to connect the carriers to an endless chain device 6 which passes over drums or sprocket wheels 7 at the ends of the chamber 1, one or both of which sprocket wheels may be positively driven. A device having this construction constitutes one form of endless conveyor, but I wish it understood that my invention may be employed in other constructions. The reticulated carriers or shelves are preferably arranged so that they will have a substantially horizontal position as they pass through the drying chamber.

In the construction herein illustrated the chamber 1 is divided into two passages 3 and at by means or" a central core 5, and the mechanism for operating the carriers 2 is ar ranged so that the carriers move up through the passage 3'anddownthrough the passage 4. \Vhere the carriers are connected to an endless-chain device, then one run of the chain will be located in the passage 3 and the other run in the passage l, said chain passing around the sprocket wheels 7 at the ends oi the core. The passage 3 is the passage in which the drying is done, the passage 4 being in the nature of a return passage for the carrier units 2.

During the drying operation the conveyer is operated so that the carriers 2 in the passage 3 move upwardly through the passage 3. Means are provided for causing a drying medium to move longitudinally through the passage 3 preferably in a downward direction so that the drying medium will move in a direction opposite to that in which the materlal to be dr1ed moves The carriers 2 are of such ashape as to extend from side means for causing a downward current of drying medium through the passage 2 may be employed. I have herein shown a suction blower 8 which is connected to the lower end of the chamber 1 and which operates to create a suction in said chamber, thus causing a downward current of drying medium in the passage 3.

In order to prevent the drying medium from being drawn downwardly through the return passage L thereby compelling all of the drying medium to pass through and over the material in the passage 3, I propose to employ a system of valve devices which are associated with the carriers 2 and which operate automatically to close the passage 4 as the carriers pass downwardly therethrough. These valve devices are shown at 9 and are in the form of flap valves that are hinged to the endless-chain device at 10. These flap valves are so situated that they are beneath the carriers 2 as the latter are moving upwardly in the passage 3, and when in this position the weight ofthe flap valves will cause them to hang downwardly in the position shown in Fig. 1, thus leaving the passage 3 free. As the carriers pass over the upper sprocket wheel 7, the flap valves 9 will drop against the underside of the carriers and will thus operate to close the passage 4. Hence the passage 4; is automatically closed to the current of drying medium while the passage 3 is always open.

Any suitable drying medium may be employed, but preferably I will use heated air. In order to make a compact structure, I propose to make the core 5 in the form of a heater for heating the air which is carried downwardly through the passage 3. The core 5 is formed a hollow chamber through which hot products of combustion may pass, said chamber having at each side thereof a plu 'ality of separate compartments 100, the compartments on one side having a staggered relation with those on the other. The compartments 100 on opposite sides of the chamber 5 are connected by lines or tubes 11 which extend through the hollow core, and the end compartment at one end of the chamber 5 is provided with an intake pipe or opening 12 through which air enters while that at the other end is provided with a delivery pipe 13 communicating with the upper end of the chamber 1.

14 indicates a furnace or heater having a smoke pipe 15 through which the hot products of combustion are delivered to the lower end of the chamber 5, said products of combustion passing upwardly through the chamber 5, and in doing so, heating the air with in the tubes or lines 11. The upper end of the chamber 5 is provided with a discharge pipe 59 through which the products of combustion escape fromsaid chamber.

The suction apparatus 8 will create a suction or reduced pressure in the passage 3, and since said passage communicates with the chambers 10 through the connection 13, such reduction of pressure will cause air to enter the inlet 12 and pass through the heated lines 11 and chambers 10 in the zigzag manner illustrated by the arrows Fig. 8, said air becoming heated in its passage through the fiues, and then passing into and downwardly through the passage 8, said hot air passing successively through the carriers 2 that are located in said passage. The drying medium, therefore, is brought into contact with the material to be dried several times in passing from one end to the other of the drying chamber therebyfacilitating the drying operation.

I will preferably so operate the suction apparatus 8 as to create a pressure less than atmospheric pressure in the chamber 3 so that the drying will be accomplished at a reduced pressure. By so doing the temperature at which evaporation takes place will 7 be reduced and the drying will be correspondingly facilitated.

IV here the material to be dried is in the nature of peat or some other similar material that requires to be ground, I propose to associate a mixing and ejecting implement in the form of a rotatable element 19 carried on and driven by a suitable shaft 20 and having a plurality of arms 21 and 22 radiating there from. The arms 21 are shown as having cutting knives 23 at the ends thereof which cooperate with the bottom of the hopper in cutting up and grinding the material. The arms 22 have shoes 2d at the ends thereof, the outer faces 25 of which stand at an angle to a radial line so that as the element 19 is;

rotated these faces 25 force the material into and through the ejection apertures 18. If the material to be dried is plastic, such as would be the case with peat after it has been cut, ground and stirred up by the implement 19, such material will be forced through the apertures 18 in the form of small pencil-like masses which will break into pencil-like fragments of varying length as they leave the apertures 18. These ejection apertures are placed directly above the lower end of the conveyer so that the material which is forced therethrough will drop onto each carrier 2 as it passes around the lower sprocket wheel 7. The material to be dried is thus delivered automatically to each carrier as it enters the drying compartment 3, and the manner of delivering the material is such that the material on each screen is in a more or less loose or open condition so that the air can freely pass therethrough.

In treating some materials it is advisable to preheat thematerial in the hopper 17 and before it is delivered to the carriers. This can be done by surrounding said hopper with a jacket 26 into which the heating medium is delivered by the suction ap aaratus 8, said suction apparatus being connected to the jacket by a pipe 27 for this purpose. 1V ith this arrangement some of the heat units which are left in the heating medium after it has performed its function in drying the material in the chamber 2 are used for preheating the material in the hopper 17. The acket 26 is provided with different connected compartments so that the heating mediumis caused to pass therethrough in a circuitous manner, said jacket having a discharge pipe 27 through which the medium is finally discharged.

In treating some material it is desirable to form it into cakesor briquets as fast as it is dried. To provide'for this I have illustrated a receiving chamber 28 at the delivery end of the conveyer into which the dried material is deposited by the carriers as they pass around the upper sprocket wheel 7. At the lower end of this receiving chamber 28 is a suitable press 29 into which material maybe delivered through the hopper or through the chute 30. The press 29 may be of any suitahle construction and is adapted to receive from the chamber28 a suitable amount of material and then to press it into briquet, brick or cake form.

Theehamber 28 is shown as provided with a discharge spout 31 through which dry material may be delivered directly to a car 32 on a track 33 if it is not desired to cake or press the dried material.

I will preferably employ a deflector plate 60 in connection with each of the carriers 2, said deflector plates operating to deflect the material as it is discharged from each carrier at the upper end of the drying chamber so as to prevent said material from being lodged on the carriers moving down through the passage 4.

I have shown at 34 an auxiliary heater which may be used to additionally heat the air if desired. This auxiliary heater is constructed similar to the heater in the chamber 1 and comprises a chamber with which the discharge pipe 59 communicates so that the products of combustion after leaving the chamber 5 may be passed through the chamber 34, said chamber having a discharge flue 3? which lead to the stack or chimney. This chamber 34 also has flues 35 extending therethrough, said flues being connected at one end to the pipe 13 and at the other end being connected with a delivber 1.

tion the products of combustion from the furnace 14 pass first through the chamber 5 ery pipe 36 which delivers into the cham- Hence when the device is in operaand then through the chamber 34 and the air which is drawn into the inlet pipe 12 passes first through the fines 11 in the chamber 5, then through the pipe 13 and the fines 35, said air being delivered through the out let 36 into the chamber 1.

I claim:

1. In a drying apparatus, the combination with a chamber divided longitudinally to constitute two passages, of an endless conveyer having its runs occupying said two passages, said conveyer comprising a plurality of reticulated carriers, means to operate said conveyer, means to deliver material to be dried to each carrier as it enters one of said passages, means to cause a drying medium to pass through said passage. and means to prevent said medium from passing through the other passage.

2. In a drying apparatus, the combination with a chamber divided longitudinally to constitute two passages, of an endless conveyer having its runs occupying said two passages, means to operate said conveyer, means to deliver material to be dried to the run of said conveyer which is occupying one of said passages, means at one end of said chamber to cause a drying medium to pass through said passage, and means to prevent said drying medium from passing through the other passage.

3. In a drying apparatus, the combination with a chamber divided longitudinally to constitute two passages, of an endless conveyer having its runs occupying said two passages, means to operate said conveyer, means to deliver material to be dried to the run of said conveyor which is occupying one of the passages, and means to cause a drying medium to pass through said passage while preventing it from passing through the other passage.

4. In a drying apparatus, .the'combination with a chamber divided longitudinally to constitute two passages, of an endless conveyer having its runs occupying said two passages, means to operate said conveyer, means to deliver material to be dried to the run of said conveyer which is occupying one of the passages, means to cause a drying medium to pass through said passage, and means associated with the conveyer to prevent said drying medium from passing through the other passage.

5. In a drying apparatus, the combination with an inclined chamber divided to form two passages extending longitudinally thereof, of an endless conveyer having its two runs occupying the two passages, means to deliver drying material to the conveyer at one end thereof, means to operate the means to cause a current of air to pass through said heating device thereby to become heated and to pass through one oi said passages, and means to deliver material to be heated to the run of the eonveyer occupying said passage.

7. in a drying apparatus, the combination with a chamber, oi an endless conveyer extending longitudinally thereof, a heating device situated between the runs of said conveyer and dividing said chamber into two passages, said heating device comprising a chamber, and heating lines extending through said chamber, means to deliver hot products of con'ibustion to said chamber, means to cause air to be drawn through said heating fines and then to be passed through one oi? said passages, and means to deliver material to be dried to the run of the conveyer occupying said passage.

In a drying apparatus, the combination with an elongated inclined chamber, of an endless conveyer extending longitudinally of said chamber and having a plurality of reticulated carriers constructed to stand in a horizontal position, means to operate said 9. In a drying apparatus, the combination with an elongated inclined chamber divided longitudinally into two passages, of an endless conveyer having its runs operating in said passages and comprisinga plurality of reticulated carriers constructed to stand in a horizontal position, means to 0perate said conveyer, said chamber having an opening leading to one end of one passage and beneath which the horizontally-arranged carriers pass successively, means to deliver continuously material to be dried through said opening by gravity, and means to cause a heating medium to pass through the passage containing the loaded carrier.

10. In a drying apparatus, the combination with an elongated inclined chamber,'of an endless conveyor extending longitudinally of said chamber and having a plurality of reticulated carriers constructed to stand in a horizontal position, means to operate said conveyer, said chamber having an opening beneath which the horizontallyarranged carriers pass successively, means continuously to deliver material to be dried through said opening by gravity in pencillike fragments whereby said material will be received on the successive horizontal carriers as the conveyer operates, and means to cause a heating medium to pass through said chamber.

11. In a drying apparatus, the combination with a chamber divided longitudinally to constitute-two passages, of a plurality of reticulated carriers adapted to contain the material to be dried, means to cause said carriers to pass through one passage in one direction and to return through the other passage, means to cause a drying medium to pass through one of said passages, and

means associated with the carriers to prevent said medium from passing through the other passage.

In testimony whereof I have signed my name to this specification.

FRED T. DOW. 

